1. Field of Invention
This invention is directed to an apparatus and method to prevent software piracy.
2. Description of the Prior Art
Computer software, by it's very nature of storage, is vulnerable to piracy. Traditional methods of distributing software, via magnetic media, are easily copied and used by non-paying "customers". Many schemes have been devised to prevent software piracy. Some are admittedly better than others.
In one case the software is protected by encoding hidden data on normally unreadable tracks. In another, the software data contains a parasite program, and is rendered unusable without the proper parasite-killer program. Both of these methods may be defeated by one of many capable sets of utility programs. Once defeated, subsequent copies can easily be made without the need for special utility programs.
One commonly used method involves the use of tables of numbers/text, or pictures, printed in a color that is difficult to reproduce on a black-and-white copier. In order to access the program, the appropriate code or picture must be matched with the random one selected by the program. The problem here is that some black-and-white copiers, when set to their darkest setting, can still reproduce the color original as a readable black-and-white facsimile. Also a color copier will usually make a suitable copy. In addition, free-hand copies can be made, and although this may take some time, once done many hundreds of photo copies may result from this one effort.
Electronic devices that connect to an input/output port of a computer will provide excellent security, but have several drawbacks. One problem is that the cost is far too high to be used with any but the most expensive software packages. Another problem is that several of these devices may have to be connected to the same port, causing an unacceptable protrusion from the computer. Also, with multiple devices, the physical strain to the port connection and increased possibility of accidental damage due to the protrusion reduce the usefulness of this device.
One of the more useful and cost-effective means for copy-protecting magnetic media is the "bad-spot" technique. Intentional defects are placed throughout the magnetic media. The locations of these defects is encoded in the program, and must be present for program execution. Thus, when you copy the program to media without these defects, the program will not run. As with other methods, a set of utility programs can detect these defect locations, which can then be replicated on the new media. However, this needs to be done for each copy, which does help to prevent subsequent generation copies by users without such utility programs. The main problem with this method of protection is that a legitimate back-up copy cannot be made. And many software users want the convenience of running programs from a mass storage device such as a fixed disk, which this method doesn't allow for.
The method of software protection by the use of optical effects overcomes the aforementioned problems and allows flexibility for use and distribution of computer programs at a reasonable cost. The transfer of a program to a mass storage device or to a back-up media is now permitted and encouraged, since the program no longer bears the burden of copy-protection. An optical device, or optical "key", is now the copy-protected element. When the optical element is a hologram, it is inherently difficult to duplicate, especially in the case of a transmission hologram. The cost to reproduce the optical key is far below that of the electronic devices mentioned, but provides the same high level of security.